Administrative Supplement Abstract This proposal responds to PA-18-591 which provides Administrative Supplements to existing National Institutes of Health grants and cooperative agreements. Specifically, the Washington State University/University of Washington Discovery Site for the Multi-Disciplinary Approach to the Study of Chronic Pelvic Pain Research Network is seeking additional funds to support epigenetic work related to the Aims of the project but not funded in the current award. The Network has transformed the study of urologic chronic pelvic pain syndromes (UCPPS) by encouraging researchers to adopt a broad, systemic view of UCPPS and use novel, multidisciplinary approaches in basic, translational, and clinical science. As part of that effort, the Network has pursued targeted data analyses to identify novel pelvic pain subtypes and urological symptom subtypes. One promising direction involves epigenetic mechanisms. DNA methylation is an important epigenetic mechanism and involves adding a methyl group to the fifth carbon of a cytosine base. DNA methylation may be related to key aspects of chronic pain, including regulation of peripheral inflammation and expression of genes related to pain processing. The transition from acute to chronic pain may also be subject to epigenetic control. The proposed study directly addresses goals outlined in the MAPP Biomarkers Protocol by developing critical data to inform translational studies related to DNA methylation and UCPPS subgroups. The Specific Aims for this Administrative Supplement are to 1) compare methylation patterns in peripheral lymphocytes obtained from UCPPS patients to determine the role of differentially methylated regions in UCPPS subgroups; and 2) examine differentially methylated regions in peripheral lymphocytes in relation to pain intensity, pain duration, and psychological functioning among all participants.